third rib clip in from the root of the wing using LP4-3 pop rivets.
As mentioned previously, the second and third ribs from the innermost rib require riveting using LP4-3 pop rivets where the web of the ribs attach to the rib clips … this is because the adjacent rib clips interfere with the body of the pneumatic squeezer preventing proper access.
Finished third rib in from the root of the wing ... AN470AD4-4 rivets attach the aft
flange onto the left spar and LP4-3 pop rivets attach the rib’s web to the rib clips.
Using the rivet gun and bucking bar to rivet the aft flange of the lone
W-1208-L nose rib onto the left spar using AN470AD4-4 rivets.
Because of the extra support needed for the wing walk area, the rib spacing is closer near the root of the wing. Unfortunately, this closeness prevented the pneumatic squeezer from having good access and almost prevents the pop riveter from having access. My standard pop riveting tool did not come close to fitting between the ribs. Fortunately, the close quarter pop riveter worked, but just barely and not without flexing the neighboring rib so the riveter’s handles could be opened enough to allow the riveter to get a second grip on the rivets … the rivets never pop during the first squeeze and require the riveter getting a second grip before they pop. It was really a chore getting Clecos in and out so needless to say, it was a fight to set the pop rivets in this area of the wing.
All ribs now riveted onto the RV-12’s left wing spar.
Better view of all the ribs riveted onto the left spar ... note the closer spacing of the nose ribs for the wing walk area.
The left wing’s stub spar assembly is the last component to complete the left wing’s skeleton. The stub spar assembly is riveted onto the nose of the inner most six ribs.
Attaching the stub spar assembly onto the W-1208 nose ribs with Clecos in preparation for riveting.
Access for the pneumatic squeezer was good enough to allow riveting the stub spar assembly onto the W-1208 nose ribs using solid rivets. AN470AD4-4.5 rivets were used to rivet the stub spar assembly onto the nose ribs …. in those areas where there was a doubler plate, AN470AD4-6 rivets were used. This was another one of those cases where the 4-6 rivets were slightly to long and the 4-5 rivet was much to short.
Using the pneumatic squeezer to set the last rivet attaching the stub spar assembly
onto the W-1208 nose ribs and thus completing the left wing skeleton.
With the stub spar assembly now fully riveted, the RV-12’s left wing skeleton is completed.
Final tally … out of the 151 rivets holding the nose ribs onto the left spar and stub spar assembly, only 12 ended up being LP4-3 pop rivets due to clearance issues with the pneumatic squeezer.